Existing communication systems provide the ability to sequence in an application to monitor a communication session. For example, the signaling channel of a communication session may have a sequenced application to provide unique services that have been identified for a particular user, such as to provide a user the ability to selectively screen calls while on another call.
As more and more sequenced applications are being used in communication systems, the need for reliable communications becomes more pronounced. Nowadays, a sequenced application may be handling hundreds of communication session at one time. If the sequenced application fails, this can result in a large number of communication sessions being dropped.
To overcome this issue, systems have been developed to failover to a backup sequenced application when a primary sequenced application fails. For example, if a primary sequenced application fails, a backup sequenced application may be selected to take over the existing communication sessions of the failed sequenced application. However, a problem exists during the time when the backup sequenced application takes over from the failed communication session. If an in-dialog message is received for one of the communication sessions during this time, the communication session is dropped because the backup sequenced application has not reestablished this particular communication session.